Nodulation, weed flora and yield of greengram (Vigna radiata) influenced by use of herbicides

A field experiment was conducted during kharif 2016 and 2017 at Research Farm, College of Agriculture, RVSKVV, Gwalior (MP) to determine the most effective herbicide/combination of herbicides to control the problematic weeds in greengram. The experiment was laid out with 10 treatments, viz quizalofop-p-ethyl 50, 75 & 100 g/ha PoE, fenoxaprop-p-ethyl 100 g/ha PoE, pendimethalin 1000 g/ha (PE), pendimethalin + imazethapyr (RM) 750 & 1000 g/ha PE, imazethapyr + imazamox (RM) 80 g/ha PoE, two hand weeding at 20 and 40 DAS and weedy check in a Randomized Block Design. The combination of post-emergence herbicide imazethapyr + imazamox (RM) 80 g/ ha was found to be very efficient in controlling the dominant grassy weeds as well as broad leaved weeds and gave maximum seed yield (993 kg/ha) followed by the cultural method of weed control where two hand weedings at 20 and 40 DAS have done (983 kg/ha). In respect of nodulation two hand weeding 20 and 40 DAS recorded maximum nodule number of 15.52/plant at 40 DAS followed by the application of imazethapyr + imazamox (RM) 80 g/ha PoE 14.45/plant. The application of imazethapyr + imazamox (RM) 80 g/ha PoE resulted in highest B:C ratio (3.03) and net returns followed by pendimethalin + imazethapyr 750 g/ha PE.